The present disclosure relates to a multi-capillary electrophoresis apparatus having a multi-capillary array formed with plural capillaries each having a sample and a separation medium filled therein. More particularly, the present disclosure relates to an apparatus that can suppress measurement fluctuations upon analysis, improve performance, and reduce run-to-run variability.
In recent years, a capillary electrophoresis apparatus including a capillary tube having an electrophoretic medium (separation medium) filled therein, such as a high-polymer polymer and a polymer solution, has been developed, as disclosed in Japanese Laid-open Patent Publication JP-A 6-138037. This capillary electrophoresis apparatus has high heat dissipation capacity and can be applied with a high voltage, in comparison to a conventional slab polymer electrophoresis apparatus. Therefore, it has the advantage that electrophoresis can be carried out at a high rate.
FIG. 10 shows a schematic structure of a known capillary electrophoresis apparatus. As shown in FIG. 10, the capillary electrophoresis apparatus B has a capillary component 103, a temperature regulated chamber 105, a detector component 107 and a buffer container 111.
The capillary component 103 is formed with plural capillaries 103a. The buffer container 111 is filled with a buffer solution 111a. A sample and a separation medium for separating the sample are filled into the capillaries 103a. Ends 103b of the capillaries 103a are immersed in the buffer solution 111a. The other ends 103c of the capillaries 103a are also immersed in, for example, a buffer solution.
The detector component 107 includes a retaining component 107b for retaining the capillaries 103a. The detector component 107 is housed in the retaining component 107b and a cover member 108. A high voltage is applied between the ends 103b and the other ends 103c of the capillaries 103a, whereby the sample is electrophoresed in the separation medium. The sample thus separated by electrophoresis is detected in the detector component 107 with an optical mechanism. The retaining component 107b has a window component 107c for capturing fluorescence excited by the optical mechanism.
In the capillary electrophoresis apparatus, Joule heat is generated upon applying a high voltage between both ends 103b and 103c of the capillary 103a. As a result, air dissolved in the liquid of the separation medium forms bubbles upon exposure to this increase in temperature to raise the resistance of the separation medium. When the separation medium has a high resistance, the electrophoresis migration velocity is lowered to cause adverse affects, such as deterioration in resolution power of the sample.